To Your Health-May 12, 2005

Chance of Lyme disease 5 percent, but don’t panic!

By: Dr. Terry Shlimbaum
   Lyme disease is caused by bacteria transmitted by the bite of a deer tick.
   Deer ticks can be as small as a pinhead and difficult to see. If not disturbed, a tick will remain attached to a person’s skin and feed there for three to six days.
   The longer a tick is attached, the greater the chance of being infected by the tick. For Lyme disease to be transmitted, the tick needs to be attached for at least 36 to 48 hours.
   At least 50 percent of deer ticks in Hunterdon County carry the Lyme bacteria. Your chance of getting Lyme disease from a tick bite in Hunterdon County is about 5 percent, that is, five tick bites out of 100 results in Lyme disease.
   Lyme disease has been divided into three stages. If treated with antibiotics, it does not progress from one stage to the next.
   Stage one occurs as soon as two days after the tick bite. A unique rash develops in 90 percent of children and probably a similar percent of adults, though many never notice it.
   The rash, called "erythema migrans," looks like a red ring or bull’s-eye that starts where the person was bitten and expands in size. Rarely, a patient may have multiple bull’s-eye spots.
   The rash is usually not painful or itchy and lasts two weeks to two months. A flu-like illness including fever, chills, muscle aches, and headache, also may develop.
   Stage two occurs two to 12 weeks after the tick bite. It develops in only 15 percent of the people who have not gotten treatment for the disease.
   The main symptoms are related to the nervous system, for example, stiff neck or weak facial muscles. Very rarely, this may cause some abnormalities of heart rhythm.
   Stage three occurs six weeks to two years after the tick bite. Often these people have had no stage two symptoms. The main symptom of this stage is recurrent attacks of painful, swollen joints (arthritis). It usually affects the knees.
   Prevention of Lyme disease is accomplished by avoiding tick bites. Remember the deer tick must be attached for 36 to 48 hours to transmit the infection so carefully inspecting your child and yourself for ticks every day from head to toe is critical.
   If a tick is discovered, grasp it with tweezers as close to the skin as possible and apply gentle sustained traction until the tick "lets go." Try to avoid crushing the tick.
   Once removed, cleanse the areas with soap and water. If the head of the tick is left in the skin, remove it as you would remove a splinter. If you cannot remove the last bits of the tick, simply cleanse the area and observe; the body’s natural defenses will take care of the debris.
   A small red area often develops around the bite, usually less than the size of a quarter and resembling the redness seen after any insect bite. This usually fades in a day or so, does not enlarge to become a "bull’s-eye" and is no cause for concern.
   Incorrect tick removal methods include using nail polish, a burning match, petroleum jelly, etc. The only correct way to remove a tick is by gently pulling it off. Dispose of the tick once removed.
   While laboratories are capable of testing live ticks for the presence of Lyme bacteria, I do not recommend this for two reasons. First, the laboratory warns a negative test does not assure the tick did not have Lyme bacteria, and second, a positive test does not mean the bacteria was transmitted.
   Remember, one in three ticks in our area have the bacteria but only one in a hundred bites result in Lyme disease!
   If you are not sure if the tick is a deer tick, you may save it for identification.
   Many expert resources recommend wearing long-sleeved shirts, pants tucked into socks and avoiding woody or grassy areas. However, most parents find these recommendations difficult to follow.
   Insect repellents such as DEET are effective but when used incorrectly or in large amounts, can be toxic to a child’s nervous system. I, therefore, suggest you use them sparingly and in low concentrations — maximum at 10 percent for children; 30 percent for adults.
   Similarly, if your child or pet plays in your yard, using insecticides on your lawn carries potential risk. Pets also should be inspected for ticks.
   At least one study has shown if a tick is engorged, and antibiotics are given within 48 hours after a tick bite, this may prevent Lyme disease. Some physicians do not embrace this study because of concerns of follow-up testing.
   You should discuss this with your physician.
   Lyme disease is diagnosed by symptoms, particularly in the early stages. Laboratory testing confirms certain cases, but is not always necessary. The blood test for Lyme disease measures the body’s immune response to the bacteria instead of looking for the bacteria itself and will, therefore, be negative early on during the infection.
   Effective treatment may or may not interfere with future test results so follow-up testing is not recommended. We confirm positive Lyme results with a special highly accurate test called a Western Blot because there is a high false positive rate for the basic test, the titer.
   Lyme testing is not a screening test and should not be used in patients without symptoms. The urine test has such a high false positive rate it is not approved by the Food and Drug Administration or Centers for Disease Control and should never be used.
   Treatment for Lyme disease is antibiotics. Most cases are cured with three to four weeks of oral medication. Advanced cases may need antibiotics through an intravenous route.
   If the symptoms don’t respond to the simple treatment, the diagnosis was probably wrong. Sometimes the minimal symptoms, such as joint aches, may last longer than the course of the antibiotic; additional antibiotics are not needed in this case because the symptoms are a result of the body’s reaction to the dead bacteria.
   A final word of caution regarding Lyme disease; don’t panic! This illness has been the center of a tremendous amount of media attention and, unfortunately, there is no shortage of misinformation to confuse you.
   Please always consider the source of information you have been given, and if you are not sure that what you are hearing or reading is true, ask us! Some so-called "experts" may not have your best interests at heart.